I have been very satisfied with my ESS VT-1 535 kit. It provides the type of power that an M-3 really should have had "right out of the box". With that said, I would consider adding a small amount of additional boost using a slightly smaller pulley on the blower. I know some VT-1 535 owners have done this, but I don't have a sense of the results they have experienced.

I really don't have a desire to move up to a VT-2 or a VT-3 kit. Obviously, those options generate insane power, but I am already very happy with what I have. If the pulley change gives a little more power with no negative consequences, then I would likely go that route.

Do it. Who cares about the kits warranty. Your not likely to use it. An IMO the supercharger itself is the only item that could really have an issue. Eveything else is metal and bolts. Not a bad upgrade if you ask me. Keep in mind the 535 still isn't intercooled so I wouldn't go crazy

Finding out the injector size is difficult. Do you think ESS or these tuners want to release their secrets and hard earned R/D. Gains from stock exhaust to catless are approx 20-25 whp. Gains from 535 to 575 pulley only are minimal. I saw approx 15whp. You would get more from upgrading to the 575 kit because the car is then tuned for it and the injectors are different. IMO - if your upgrading from 535....just go to the 600 or 625.

Finding out the injector size is difficult. Do you think ESS or these tuners want to release their secrets and hard earned R/D. Gains from stock exhaust to catless are approx 20-25 whp. Gains from 535 to 575 pulley only are minimal. I saw approx 15whp. You would get more from upgrading to the 575 kit because the car is then tuned for it and the injectors are different. IMO - if your upgrading from 535....just go to the 600 or 625.

It's not difficult at all and certainly not a secret. I believe they're Bosch 40lbs but may be wrong. A shop would be able to flow test them to calculate they're size though.

It really seems like unnecessary hassle and risk for minimal power gain. OP, do you have a full exhaust? If not, that's your power gain right there...

Adding a smaller pulley to the current VT1-535 would net you min gains but would lower your safety margin without proper changes to the software. On average you might pickup about 10-15 whp. The down side is the safety calculations in the software are configured to keep the motor safe in most conditions with the current level of boost. One of the changes we make in our higher boost kits is we use a different tune knowing that the vehicle is adding intercooling or is going to be on high quality 93+ octane fuel. In the case of the VT1-535 non intercooled kit we would actually add more safety margin to the current tune if we were going to run higher levels of boost on it. This would allow it to make a small amount of additional power in proper conditions but also keep it safe when needed.

Adding a smaller pulley to the current VT1-535 would net you min gains but would lower your safety margin without proper changes to the software. On average you might pickup about 10-15 whp. The down side is the safety calculations in the software are configured to keep the motor safe in most conditions with the current level of boost. One of the changes we make in our higher boost kits is we use a different tune knowing that the vehicle is adding intercooling or is going to be on high quality 93+ octane fuel. In the case of the VT1-535 non intercooled kit we would actually add more safety margin to the current tune if we were going to run higher levels of boost on it. This would allow it to make a small amount of additional power in proper conditions but also keep it safe when needed.

+1.

OP: You'll pick up more power going with a set of Macht Schnell Track Pipes.

Finding out the injector size is difficult. Do you think ESS or these tuners want to release their secrets and hard earned R/D. Gains from stock exhaust to catless are approx 20-25 whp. Gains from 535 to 575 pulley only are minimal. I saw approx 15whp. You would get more from upgrading to the 575 kit because the car is then tuned for it and the injectors are different. IMO - if your upgrading from 535....just go to the 600 or 625.

Any x-pipe with the primary cats removed will help. If you're on a budget, just take a good muffler shop and have the cats removed. Probably the cheapest 20 RWHP you will pick up. The next cheapest option would be a catless x-pipe. It will be loud however. The best of all worlds is probably a titanium exaust with high flow cats like the Akra Evolution but probably going to throw you back $6K or so.